Biomass treatment for hydrothermal hydrocatalytic conversion

ABSTRACT

A selective removal of metal and its anion species that are detrimental to subsequent hydrothermal hydrocatalytic conversion from the biomass feed prior to carrying out catalytic hydrogenation/hydrogenolysis/hydrodeoxygenation of the biomass in a manner that does not reduce the effectiveness of the hydrothermal hydrocatalytic treatment while minimizing the amount of water used in the process is provided.

The present non-provisional application claims the benefit of pendingU.S. Provisional Patent Application Ser. No. 61/917406, filed Dec. 18,2013, the entire disclosure of which is hereby incorporated byreference.

FIELD OF THE INVENTION

The invention relates to treatment of biomass for the hydrothermalhydrocatalytic treatment in the production of higher hydrocarbonssuitable for use in transportation fuels and industrial chemicals frombiomass. More specifically, the invention relates to removal ofdetrimental species from the biomass for an effective biomasshydrothermal hydrocatalytic conversion.

BACKGROUND OF THE INVENTION

A significant amount of attention has been placed on developing newtechnologies for providing energy from resources other than fossilfuels. Biomass is a resource that shows promise as a fossil fuelalternative. As opposed to fossil fuel, biomass is also renewable.

Biomass may be useful as a source of renewable fuels. One type ofbiomass is plant biomass. Plant biomass is the most abundant source ofcarbohydrate in the world due to the lignocellulosic materials composingthe cell walls in higher plants. Plant cell walls are divided into twosections, primary cell walls and secondary cell walls. The primary cellwall provides structure for expanding cells and is composed of threemajor polysaccharides (cellulose, pectin, and hemicellulose) and onegroup of glycoproteins. The secondary cell wall, which is produced afterthe cell has finished growing, also contains polysaccharides and isstrengthened through polymeric lignin covalently cross-linked tohemicellulose. Hemicellulose and pectin are typically found inabundance, but cellulose is the predominant polysaccharide and the mostabundant source of carbohydrates. However, production of fuel fromcellulose poses a difficult technical problem. Some of the factors forthis difficulty are the physical density of lignocelluloses (like wood)that can make penetration of the biomass structure of lignocelluloseswith chemicals difficult and the chemical complexity of lignocellulosesthat lead to difficulty in breaking down the long chain polymericstructure of cellulose into carbohydrates that can be used to producefuel. Another factor for this difficulty is the nitrogen compounds andsulfur compounds contained in the biomass. The nitrogen and sulfurcompounds contained in the biomass can poison catalysts used insubsequent processing.

Most transportation vehicles require high power density provided byinternal combustion and/or propulsion engines. These engines requireclean burning fuels which are generally in liquid form or, to a lesserextent, compressed gases. Liquid fuels are more portable due to theirhigh energy density and their ability to be pumped, which makes handlingeasier.

Currently, bio-based feedstocks such as biomass provide the onlyrenewable alternative for liquid transportation fuel. Unfortunately, theprogress in developing new technologies for producing liquid biofuelshas been slow in developing, especially for liquid fuel products thatfit within the current infrastructure. Although a variety of fuels canbe produced from biomass resources, such as ethanol, methanol, andvegetable oil, and gaseous fuels, such as hydrogen and methane, thesefuels require either new distribution technologies and/or combustiontechnologies appropriate for their characteristics. The production ofsome of these fuels also tends to be expensive and raise questions withrespect to their net carbon savings. There is a need to directly processbiomass into liquid fuels, amenable to existing infrastructure.

Processing of biomass as feeds is challenged by the need to directlycouple biomass hydrolysis to release sugars, and catalytichydrogenation/hydrogenolysis/hydrodeoxygenation of the sugar, to preventdecomposition to heavy ends (caramel, or tars). Further, it is achallenge to minimize generation of waste products that may requiretreating before disposal and/or catalyst deactivation by poisons.

SUMMARY OF THE INVENTION

It was found desirable to remove detrimental species from the biomassfeed prior to carrying out catalytichydrogenation/hydrogenolysis/hydrodeoxygenation of the biomass in amanner that does not reduce the effectiveness of the hydrothermalhydrocatalytic treatment while minimizing the amount of water used inthe process.

In one embodiment, a method for selective removal of detrimental metalsand their anion species from cellulosic biomass solids is providedcomprising:

-   -   a. providing a detrimental species-containing cellulosic biomass        solids;    -   b. introducing said detrimental species-containing cellulosic        biomass solids from an inlet into a treatment vessel, said        cellulosic biomass solids having a true interstitial volume in        said vessel;    -   c. introducing an acidic solution having a pH of at most 4 from        an inlet to said cellulosic biomass solids containing vessel at        a temperature in the range of 0° C. to 60° C. in an amount to        fill at least about 5% bed volume to at most about 40% bed        volume of said true interstitial volume;    -   d. subsequently to step c, introducing an aqueous solution        having a pH of at least 5 from an inlet to said acidic        cellulosic biomass solids-containing vessel, thereby producing        washed cellulosic biomass solids having reduced detrimental        species content compared to the detrimental species-containing        cellulosic biomass solids and an acidic water effluent, wherein        said acidic water effluent is in the range of about 3 parts to        about 0.5 parts relative to about 1 part of detrimental        species-containing cellulosic biomass solids (dry basis);    -   e. introducing a removal stream comprising a gas stream or an        organic solvent solution from an inlet to the vessel containing        the washed cellulosic biomass solids thereby producing a        pretreated cellulosic biomass solids with reduced water content        compared to the water washed cellulosic biomass solids and an        aqueous effluent;    -   f. discharging the pretreated cellulosic biomass solids from an        outlet and transferring at least a portion of the discharged        pretreated biomass solids to a digestion and/or reaction zone;    -   g. recycling at least a first portion of the aqueous effluent to        produce acidic solution; and    -   h. recycling at least a second portion of the aqueous effluent        as an aqueous solution.

In another embodiment, a method for selective removal of detrimentalmetals and their anion species from cellulosic biomass solids isprovided comprising:

-   -   a. providing a detrimental species-containing cellulosic biomass        solids;    -   b. introducing said detrimental species-containing cellulosic        biomass solids from an inlet into a treatment vessel, said        cellulosic biomass solids having a true interstitial volume in        said vessel;    -   c. introducing an acidic solution having a pH of at most 4 from        an inlet to said cellulosic biomass solids containing vessel at        a temperature in the range of 0° C. to 60° C. in an amount to        fill at least about 5% bed volume to at most about 40% bed        volume of said true interstitial volume;    -   d. subsequently to step c, introducing an aqueous solution        having a pH of at least 5 from an inlet to said acidic        cellulosic biomass solids-containing vessel, thereby producing        washed cellulosic biomass solids having reduced detrimental        species content compared to the detrimental species-containing        cellulosic biomass solids and an acidic water effluent;    -   e. introducing a base solution having a pH of at least 9 from an        inlet to said washed cellulosic biomass solids containing vessel        at a temperature in the range of 0° C. to 60° C. in an amount to        fill at least about 5% bed volume to at most about 40% bed        volume of said true interstitial volume;    -   f. subsequently to step e, introducing an aqueous solution        having a pH of at most 8 from an inlet to said basic cellulosic        biomass solids-containing vessel, thereby producing second        washed cellulosic biomass solids having reduced detrimental        species content compared to the detrimental species-containing        cellulosic biomass solids and an basic water effluent;    -   g. wherein the combined amount of said acidic water effluent and        said basic water effluent is in the range of about 3 parts to        about 0.5 parts relative to about 1 part of detrimental        species-containing cellulosic biomass solids (dry basis)    -   h. introducing a removal stream comprising a gas stream or an        organic solvent solution from an inlet to the vessel containing        the second washed cellulosic biomass solids thereby producing a        pretreated cellulosic biomass solids with reduced water content        compared to the second water washed cellulosic biomass solids        and a second aqueous effluent;    -   i. discharging the pretreated cellulosic biomass solids from an        outlet and transferring at least a portion of the discharged        pretreated biomass solids to a digestion and/or reaction zone;    -   j. recycling at least a first portion of the aqueous effluent to        produce acidic solution;    -   k. recycling at least a first portion of the second aqueous        effluent to produce base solution; and    -   l. recycling at least a second portion of the aqueous effluent        and at least a second portion of the second aqueous effluent as        an aqueous solution.

In yet another embodiment, a method for selective removal of detrimentalmetals and their anion species from cellulosic biomass solids isprovided comprising:

-   -   a. providing a detrimental species-containing cellulosic biomass        solids;    -   b. introducing said detrimental species-containing cellulosic        biomass solids from an inlet into a treatment vessel, said        cellulosic biomass solids having a true interstitial volume in        said vessel;    -   c. introducing a base solution having a pH of at least 9 from an        inlet to said cellulosic biomass solids containing vessel at a        temperature in the range of 0° C. to 60° C. in an amount to fill        at least about 5% bed volume to at most about 40% bed volume of        said true interstitial volume;    -   d. subsequently to step c, introducing an aqueous solution        having a pH of at most 8 from an inlet to said basic cellulosic        biomass solids-containing vessel, thereby producing washed        cellulosic biomass solids having reduced detrimental species        content compared to the detrimental species-containing        cellulosic biomass solids and an basic water effluent;    -   e. introducing a base solution having a pH of at most 4 from an        inlet to said washed cellulosic biomass solids containing vessel        at a temperature in the range of 0° C. to 60° C. in an amount to        fill at least about 5% bed volume to at most about 40% bed        volume of said true interstitial volume;    -   f. subsequently to step e, introducing an aqueous solution        having a pH of at least 5 from an inlet to said basic cellulosic        biomass solids-containing vessel, thereby producing second        washed cellulosic biomass solids having reduced detrimental        species content compared to the detrimental species-containing        cellulosic biomass solids and an acidic water effluent;    -   g. wherein the combined amount of said acidic water effluent and        said basic water effluent is in the range of about 3 parts to        about 0.5 parts relative to about 1 part of detrimental        species-containing cellulosic biomass solids (dry basis)    -   h. introducing a removal stream comprising a gas stream or an        organic solvent solution from an inlet to the vessel containing        the second washed cellulosic biomass solids thereby producing a        pretreated cellulosic biomass solids with reduced water content        compared to the second water washed cellulosic biomass solids        and a second aqueous effluent;    -   i. discharging the pretreated cellulosic biomass solids from an        outlet and transferring at least a portion of the discharged        pretreated biomass solids to a digestion and/or reaction zone;    -   j. recycling at least a first portion of the aqueous effluent to        produce base solution;    -   k. recycling at least a first portion of the second aqueous        effluent to produce acidic solution; and    -   l. recycling at least a second portion of the aqueous effluent        and at least a second portion of the second aqueous effluent as        an aqueous solution.

In yet another embodiment, in the digestion and/or reaction zone of theabove methods, the treated cellulosic biomass is contacted with ahydrothermal hydrocatalytic catalyst in the presence of hydrogen and adigestion solvent thereby producing an intermediate oxygenated productstream comprising oxygenated hydrocarbons and water; and at least aportion of the water is separated and recycled to form at least aportion of the aqueous solution.

In yet another embodiment, in the digestion and/or reaction zone in theabove methods, the treated cellulosic biomass is contacted with ahydrothermal hydrocatalytic catalyst in the presence of hydrogen and adigestion solvent thereby producing an intermediate oxygenated productstream; at least a portion of the oxygenated intermediate product streamis converted to a hydrocarbon product stream comprising hydrocarbons andwater; and at least a portion of the water is separated and recycled toform at least a portion of the aqueous solution. The oxygenatedintermediate product steam may comprise oxygenated hydrocarbons andwater, and at least a portion of the water maybe separated and recycledto form at least a portion of the aqueous solution.

The features and advantages of the invention will be apparent to thoseskilled in the art. While numerous changes may be made by those skilledin the art, such changes are within the spirit of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment, the invention relates to selective removal ofdetrimental metals and their anions, such as chlorine, from adetrimental species-containing cellulosic biomass solid. Any suitable(e.g., inexpensive and/or readily available) type of lignocellulosicbiomass can be used. Suitable lignocellulosic biomass can be, forexample, selected from, but not limited to, wood, forestry residues,agricultural residues, herbaceous material, municipal solid wastes, pulpand paper mill residues, and combinations thereof. Thus, in someembodiments, the biomass can comprise, for example, corn stover, straw,bagasse, miscanthus, sorghum residue, switch grass, duckweed, bamboo,water hyacinth, hardwood, hardwood chips, hardwood pulp, softwood,softwood chips, softwood pulp, and/or combination of these feedstocks.The biomass can be chosen based upon a consideration such as, but notlimited to, cellulose and/or hemicelluloses content, lignin content,growing time/season, growing location/transportation cost, growingcosts, harvesting costs and the like. These cellulosic biomass solidscontain metal species and its corresponding anions such as Mg, Ca, Na, KFe, Mn, Cl, SO₄, PO₄, NO₃ that are detrimental to catalysts or equipmentused in the hydrothermal hydrocatalytic treatment of the biomass(“detrimental species”). Hence, it is desirable to at least in partremove these detrimental species from the cellulosic biomass solidsbefore the hydrothermal hydrocatalytic treatment of biomass.

The oxygenated hydrocarbons produced from the hydrothermalhydrocatalytic process are useful in the production of higherhydrocarbons suitable for use in transportation fuels and industrialchemicals from biomass. The higher hydrocarbons produced are useful informing transportation fuels, such as synthetic gasoline, diesel fuel,and jet fuel, as well as industrial chemicals. As used herein, the term“higher hydrocarbons” refers to hydrocarbons having an oxygen to carbonratio less than the oxygen to carbon ratio of at least one component ofthe biomass feedstock. As used herein the term “hydrocarbon” refers toan organic compound comprising primarily hydrogen and carbon atoms,which is also an unsubstituted hydrocarbon. In certain embodiments, thehydrocarbons of the invention also comprise heteroatoms (i.e., oxygensulfur, phosphorus, or nitrogen) and thus the term “hydrocarbon” mayalso include substituted hydrocarbons. As used herein, the term “solublecarbohydrates” refers to monosaccharides or polysaccharides that becomesolubilized in a digestion process. Although the underlying chemistry isunderstood behind digesting cellulose and other complex carbohydratesand further transforming simple carbohydrates into organic compoundsreminiscent of those present in fossil fuels, high-yield andenergy-efficient digestion processes suitable for converting cellulosicbiomass into fuel blends have yet to be developed. In this regard, themost basic requirement associated with converting cellulosic biomassinto fuel blends using digestion and other processes is that the energyinput needed to bring about the conversion should not be greater thanthe available energy output of the product fuel blends. Further theprocess should maximize product yield while minimizing waste products.These basic requirements lead to a number of secondary issues thatcollectively present an immense engineering challenge that has not beensolved heretofore.

Further, the removal of these detrimental species is complicated by thesensitivity of the catalysts for the hydrothermal hydrocatalytictreatment to the reaction conditions. Processing of biomass as feeds ischallenged by the need to directly couple biomass hydrolysis to releasesugars, and catalytic hydrogenation/hydrogenolysis/hydrodeoxygenation ofthe sugar, to prevent decomposition to heavy ends (caramel, or tars).For example, too much water from a wash process can dilute the reactionstream and require removal of larger amounts of water from the processand may further lead to stress on the catalyst used in the process.Further, removal of water at a later stage by thermally separating thewater will require a large amount of energy. It is also desirable torecycle the wash water to minimize or eliminate the need for other waterinputs to the process.

In further embodiment, the invention relates recycling the water used towash the biomass and to minimizing the amount of waste water generatedin the process. The invention balances the competing advantage ofselective removal of detrimental metal species and its anion, such aschlorine, from a detrimental species-containing cellulosic biomasssolids while not reducing the effectiveness of the hydrothermalhydrocatalytic treatment while minimizing the amount of water used inthe process. Applicants have found that washing the biomass with diluteacids (mild acidic conditions) at low temperature effectively removes atleast a portion of the detrimental species in the biomass withoutremoval of carbohydrates. However a large amount of water required toremove the detrimental species also hinders and/or creates more processwater that requires more water removal and disposals. The process of theinvention provides effective solutions to these problems.

It is also important in the wash process to prevent the hydrolysis ofwood and loss of carbohydrate to the wash effluent (or aqueous solutioneffluent). Thus it is preferable to maintain the treatment of thebiomass to at most about 60° C. The loss of carbohydrate is preferablyless than 10% by weight, more preferably less than 5% by weight, evenmore preferably less than 2% by weight based on the carbohydratespresent in the biomass (dry basis).

Prior to treatment, the untreated biomass can be reduced in size (e.g.,chopping, crushing or debarking) to a convenient size and certainquality that aids in moving the biomass or mixing and impregnating thechemicals from digestive solvent. Thus, in some embodiments, providingbiomass can comprise harvesting a lignocelluloses-containing plant suchas, for example, a hardwood or softwood tree. The tree can be subjectedto debarking, chopping to wood chips of desirable thickness, and washingto remove any residual soil, dirt and the like.

It is preferable to render the biomass feed (wood chips or other) freeof entrained air, and densified to insure the feedstock will sink inwater or solvent, vs. float (pre-conditioning). Floating can occur ifthe feed is allowed to dry during storage, upon which air may enterpores and be transported into the process.

Densification via impregnation with water or solvent may be effected bysoaking in water or solvent. Pressurization of the water or solvent willforce liquid into pores. One of the most effective ways to drive gas(air or non-condensibles) out of the pore of the biomass is to contactthe biomass with solvent vapor, most preferable water vapor or steam.

Typically, this is done by supplying low pressure steam (nominal 1-2atmospheres above ambient pressure) to the bottom of a storage bin, andallowing the steam or solvent vapor to travel upwards through the bin ofsolids, to drive out air or entrained gas. Contacting of water orsolvent vapor at a temperature above the biomass temperature results incondensation of liquid water or vapor in the pores of the biomass,driving gas out of the pores. This saturates and densifies the biomasssuch that it now has a density greater than water or solvent, andtherefore sinks when added to liquid water or solvent during the washprocess.

The time and duration of the steaming should be controlled such that thetemperature of the biomass does not exceed about 60 degrees centigradefor an extended period of time. Specifically, one can supply steam attemperatures above 100 degrees centigrade (the boiling point of water),to biomass initially at ambient temperature (below about 35 degreescentigrade), for a period of time such that the final temperature of thebiomass does not exceed about 60 degrees centigrade, or if temperatureabove 60 degree centigrade, the exposure at this temperature is limitedto less than 60 minutes, preferably less than 30 minutes, and mostpreferably less than about 10 minutes. By minimizing the exposure totemperatures above 60° C., hydrolysis and degradation of carbohydratecomponents is minimized, and loss of these components to the waterand/or acid and base wash process steps can be minimized to less than 5%of the carbohydrate portion of the biomass, most preferably less than1%.

The detrimental species-containing cellulosic biomass solids isintroduced in to a treatment vessel from an inlet, thus the cellulosicbiomass solids have a true interstitial volume in such vessel.

The vessel can be in any shape that include, for example, vertical,horizontal, incline, and may include bends, curves or u shape. Thevessel will further have at least one inlet and at least one outlet.

In one embodiment, an acidic solution having a pH of at most 4,preferably having a pH of at least 0, more preferably having a pH in therange of 0 to 3 at a temperature in the range of 0° C. to 60° C.,preferably in the range of 10 to 45° C., is introduced from an inlet tothe cellulosic biomass solids containing vessel to obtain an acidiccellulosic biomass solids-containing biomass. The inlet may be the sameinlet as the biomass solids introduction or a separate, second inlet tothe treatment vessel. The acidic solution is introduced in an amount tofill at least about 5% bed volume to at most about 40% bed volume ofsuch true interstitial volume.

After the acidic solution introduction, an aqueous solution having a pHof at least 5 is introduced from an inlet to the acidic cellulosicbiomass solids-containing vessel producing washed cellulosic biomasssolids having reduced detrimental species content compared to thedetrimental species-containing cellulosic biomass solids and an acidicwater effluent. The inlet may be the same inlet as the biomass solidsintroduction, the acidic solution inlet, or a separate, second or thirdinlet to the treatment vessel. The acidic water effluent and the treatedcellulosic biomass solids may be removed from the treatment vessel fromthe same outlet or a separate, second, outlet.

The acid wash is carried out so that the amount of the acidic watereffluent from the treatment vessel is in the range of about 3 parts toabout 0.5 parts, preferably in the range of about 2 parts to about 1part relative to the cellulosic biomass solids (dry basis) charged tothe treatment step, based on weight.

Interstitial volume is the drainable volume of liquid in the bed, notoccupied by liquid-saturated biomass. It may be determined by firstfilling a vessel with biomass that has been pre-densified e.g. bysteaming, to insure that it will not float when water, aqueous mixtures,or solvent is introduced to the vessel. Interstitial volume can best bedetermined by filling upflow with liquid from the bottom of the vessel,after initially filling the vessel with biomass saturated with water orsolvent. The interstitial volume is the amount of liquid added to justcover the top of the biomass bed.

After introduction of aqueous solution, a gas stream or an organicsolvent solution is introduced to the vessel containing the washedcellulosic biomass solids, producing a pretreated cellulosic biomasssolids with reduced water content compared to the water washedcellulosic biomass solids and an aqueous effluent. The inlet may be thesame inlet as the biomass solids introduction, the acidic solutioninlet, the aqueous solution inlet or a separate, second, third or fourthinlet to the treatment vessel. The aqueous effluent and the pretreatedcellulosic biomass solids may be removed from the treatment vessel fromthe same outlet or a separate, second or third, outlet. In this waterdisplacement step, the water content is reduced by at least by 5% byvolume, preferably at least by 25% by volume, more preferably at leastby 50% by volume, based on the liquid constituent of the water washedcellulosic biomass solids. The gas may be air, hydrogen, nitrogen,steam, organic vapors, and mixtures thereof. The organic solvent ispreferably in situ generated. Preferably, the organic solvent is asolvent (digestive solvent) used in the digestion and/or reaction zone.

The pretreated cellulosic biomass solids is discharged from an outlet ofthe treatment vessel, then transferred to a digestion and/or reactionzone.

At least a portion of the aqueous effluent is recycled to produce acidicsolution and/or aqueous solution.

In another embodiment, after the aqueous solution is introduced to thebiomass solids containing vessel, optionally a base solution having a pHof greater than 9, preferably having a pH of at least 10, preferablyhaving a pH of at most 13, more preferably having a pH in the range of10 to 13, may be introduced to the vessel containing the washedcellulosic biomass solids at a temperature in the range of 0° C. to 60°C., preferably in the range of 10 to 45° C., producing a basiccellulosic biomass solids. The inlet may be the same inlet as thebiomass solids introduction or a separate, second inlet to the treatmentvessel. The acidic solution is introduced in an amount to fill at leastabout 5% bed volume to at most about 40% bed volume of such trueinterstitial volume.

After the base solution introduction, an aqueous solution having a pH ofhaving a pH of at least 5 to at most 9 is introduced from an inlet tothe basic cellulosic biomass solids-containing vessel producing treated(or based washed in such embodiment) cellulosic biomass solids havingreduced detrimental species content compared to the detrimentalspecies-containing cellulosic and a basic water effluent. The inlet maybe the same inlet as the biomass solids introduction, the acidicsolution inlet, the aqueous solution inlet, or a separate, second orthird or fourth inlet to the treatment vessel. The basic water effluent,the acidic water effluent, the aqueous effluent, and the treatedcellulosic biomass solids may be removed from the treatment vessel fromthe same outlet or a separate, second, third or fourth outlet.

The base wash is carried out so that the amount of the total of acidicwater effluent and basic water effluent from the treatment vessel is inthe range of about 3 parts to about 0.5 parts, preferably in the rangeof about 2 parts to about 1 part relative to the cellulosic biomasssolids (dry basis) charged to the treatment step, based on weight.

After introduction of aqueous solution, a gas stream or an organicsolvent solution is introduced to the vessel containing the washedcellulosic biomass solids, producing a pretreated cellulosic biomasssolids with reduced water content compared to the water washedcellulosic biomass solids and an aqueous effluent. The inlet may be thesame inlet as the biomass solids introduction, the acidic solutioninlet, the aqueous solution inlet or a separate, second, third or fourthinlet to the treatment vessel. The aqueous effluent and the pretreatedcellulosic biomass solids may be removed from the treatment vessel fromthe same outlet or a separate, second or third, outlet. In this waterdisplacement step, the water content is reduced by at least by 5% byvolume, preferably at least by 25% by volume, more preferably at leastby 50% by volume, based on the liquid constituent of the water washedcellulosic biomass solids

The pretreated cellulosic biomass solids is discharged from an outlet ofthe treatment vessel, then transferred to a digestion and/or reactionzone.

At least a portion of the aqueous effluent is recycled to produce acidicsolution and/or aqueous solution.

In yet another embodiment, the order of the acid wash and the base washmay be reversed in a manner so that, a base solution having a pH ofgreater than 9 is introduced first from an inlet to the cellulosicbiomass solids containing vessel in an amount to fill at least about 5%bed volume to at most about 40% bed volume of said true interstitialvolume, subsequently an aqueous solution is introduced having a pH of atmost 8 from an inlet to said basic cellulosic biomass solids-containingvessel, thereby producing washed cellulosic biomass solids havingreduced detrimental species content compared to the detrimentalspecies-containing cellulosic biomass solids and an basic watereffluent; a base solution having a pH of at most 4 is introduced from aninlet to said washed cellulosic biomass solids containing vessel in anamount to fill at least about 5% bed volume to at most about 40% bedvolume of said true interstitial volume; subsequently an aqueoussolution having a pH of at least 5 is introduced from an inlet to saidbasic cellulosic biomass solids-containing vessel, thereby producingsecond washed cellulosic biomass solids having reduced detrimentalspecies content compared to the detrimental species-containingcellulosic biomass solids and an acidic water effluent. The combinedamount of said acidic water effluent and said basic water effluent is inthe range of about 3 parts to about 0.5 parts relative to about 1 partof detrimental species-containing cellulosic biomass solids (dry basis).

A removal stream comprising a gas stream or an organic solvent solutionis introduced from an inlet to the vessel containing the second washedcellulosic biomass solids producing a pretreated cellulosic biomasssolids with reduced water content compared to the second water washedcellulosic biomass solids and a second aqueous effluent, discharging thepretreated cellulosic biomass solids from an outlet and transferring atleast a portion of the discharged pretreated biomass solids to adigestion and/or reaction zone. At least a first portion of the aqueouseffluent is recycled to produce base solution. At least a first portionof the second aqueous effluent is recycled to produce acidic solution;and at least a second portion of the second aqueous effluent is recycledas an aqueous solution.

The maximum density of cellulosic biomass when loaded into a vessel orcontainer to conduct the treatments steps with a free (non-absorbed)liquid phase, will be such that the amount of water used for thesetreatments is less than the total amount of liquid required to fill thevessel or container.

Use of recycle treatment water and staged treatment zones, as describedin the present invention, is therefore required in order to produce aneffluent separated from the biomass which contains a maximumconcentrations of the detrimental removed components, in the restrictedamounts of water treatment allowed. The amounts of water prescribed willtypically correspond to the natural water content of the biomassfeedstock, augmented by any water which can be made in processconversion steps such as reaction of biomass with hydrogen, with zero orminimal use of additional water from another source. The amount ofadditional water required is thus restricted to less than 50% of thebiomass feed (dry basis), and hence would represent less than a third ofthe typical amount of additional water employed for similar processingin the manufacture of, for example, pulp used to make paper. Preferably,the amount of additional makeup water above the water naturally presentin the biomass feed, and made in the process, is zero.

The acidic solution may contain an inorganic acid or carboxylic acid(“collectively referred herein as “acids”). The inorganic acid may be,for example, sulfuric acid, phosphoric acid, hydrochloric acid, nitricacid or mixtures thereof. The acid content of the acidic solution ispreferably less than 10 wt % and at least 0.01 wt %. The inorganic acidis preferably present in an amount of 0.01 wt % to 2wt %. If sulfuricacid is used, the sulfuric acid is preferably present in an amount of0.01 wt % to 1 wt %. If phosphoric acid is used, the phosphoric acid ispreferably present in an amount of 0.01 wt % to 2 wt %. If nitric acidis used, the nitric acid is preferably present in an amount of 0.01 wt %to 1 wt %. The carboxylic acid may be, for example, acetic acid,levulinic acid, lactic acid, formic acid, propionic acid, or mixturesthereof. The carboxylic acid is preferably present in an amount of 0.1wt % to 5 wt %. If acetic acid is used, the acetic acid is preferablypresent in an amount of 0.1 wt % to 2.5 wt %.

The base solution may contain an inorganic base such as, for example,KOH, NaOH and ammonia. The base content of the base solution ispreferably less than 5 Normal and at least 0.01 Normal. The baseconcentration is preferably from about 0.1 to about 5 Normal.

Preferably, the metal species content is reduced by at least 75%, atleast 80%, at least 85%, at least 90%, at least 95%, even at least 98%or essentially completely. More particularly the non-water solublemetals such as manganese is reduced by at least 20%, at least 30%, atleast 35%, at least 40%, at least 50%, at least 60%, at least 70%, atleast 75%, at least 80%, at least 90%, at least 95%, or essentiallycompletely. Preferably the anion content such as chlorine is alsoreduced by at least 50%, at least 55%, at least 60%, at least 75%, 95%,.The term “essentially completely” means the specie is completely removedwithin the detection limit or within statistical significance or withinmeasurement errors

For the instant biofuels process, the minimization of fresh water usageis a key issue. However, due to biomass packing density being poor, atbest 3 parts or more of bed volume of water are required to typicallyfill a bed for washing one part of biomass. In the invention process,the detrimental species is removed with less than 5 parts, preferably atmost 2.5 parts, more preferably at most 2 parts, even at most 1.5 partsof water for washing one part of biomass. It is preferred that for theremoval process, only the water from the water in the biomass and watergenerated in the process

At least a portion of the treated cellulosic biomass solids is providedto a digestion and/or reaction zone (collectively referred to as“hydrothermal hydrocatalytic reaction zone”) for further processing.This zone may be conducted in a single step or in multiple steps orvessels as described below.

For the hydrothermal catalytic reaction zone, the zone may have one ormore vessels. In one embodiment in the digestion/reaction zonehydrolysis and hydrothermal hydrocatalytic reaction of the treatedbiomass is carried out in one or more vessels. These vessels may bedigesters or reactors or combination thereof including a combinationhydrothermal hydrocatalytic digestion unit.

In some embodiments, lignocellulosic biomass (solids) being continuouslyor semi-continuously added to the hydrothermal digestion unit orhydrothermal hydrocatalytic digestion unit may be pressurized beforebeing added to the unit, particularly when the hydrothermal(hydrocatalytic) digestion unit is in a pressurized state.Pressurization of the cellulosic biomass solids from atmosphericpressure to a pressurized state may take place in one or morepressurization zones before addition of the cellulosic biomass solids tothe hydrothermal (hydrocatalytic) digestion unit. Suitablepressurization zones that may be used for pressurizing and introducinglignocellulosic biomass to a pressurized hydrothermal digestion unit orhydrothermal hydrocatalytic digestion unit are described in more detailin commonly owned United States Patent Application PublicationsUS20130152457 and US20130152458, and incorporated herein by reference inits entirety. Suitable pressurization zones described therein mayinclude, for example, pressure vessels, pressurized screw feeders, andthe like. In some embodiments, multiple pressurization zones may beconnected in series to increase the pressure of the cellulosic biomasssolids in a stepwise manner The digestion and the hydrothermalhydrocatalytic reaction in the hydrothermal catalytic reaction zone (ordigestion reaction zone) may be conducted separately, partiallycombined, or in situ.

In some embodiments, the digestion rate of cellulosic biomass solids maybe accelerated in the presence of a liquid phase containing a digestionsolvent. In some instances, the liquid phase may be maintained atelevated pressures that keep the digestion solvent in a liquid statewhen raised above its normal boiling point. Although the more rapiddigestion rate of cellulosic biomass solids under elevated temperatureand pressure conditions may be desirable from a throughput standpoint,soluble carbohydrates may be susceptible to degradation at elevatedtemperatures. One approach for addressing the degradation of solublecarbohydrates during hydrothermal digestion is to conduct an in situcatalytic reduction reaction process so as to convert the solublecarbohydrates into more stable compounds as soon as possible after theirformation.

In certain embodiments, a slurry catalyst may be effectively distributedfrom the bottom of a charge of cellulosic biomass solids to the topusing upwardly directed fluid flow to fluidize and upwardly conveyslurry catalyst particulates into the interstitial spaces within thecharge for adequate catalyst distribution within the digestingcellulosic biomass solids. Suitable techniques for using fluid flow todistribute a slurry catalyst within cellulosic biomass solids in such amanner are described in commonly owned United States Published PatentApplications US20140005445 and US20140005444and incorporated herein byreference in its entirety. In addition to affecting distribution of theslurry catalyst, upwardly directed fluid flow may promote expansion ofthe cellulosic biomass solids and disfavor gravity-induced compactionthat occurs during their addition and digestion, particularly as thedigestion process proceeds and their structural integrity decreases.Methods of effectively distributing molecular hydrogen within cellulosicbiomass solids during hydrothermal digestion is further described incommonly owned United States Published Patent Applications US20140174433and US20140174432 and incorporated herein by reference in its entirety.

In another embodiment the hydrothermal hydrocatalytic digestion unit maybe configured as disclosed in a co-pending United States PublishedPatent Application No. US20140117276 which disclosure is herebyincorporated by reference. In the digestion zone, the size-reducedbiomass is contacted with the digestive solvent where the digestionreaction takes place. The digestive solvent must be effective to digestlignins.

In some embodiments, at least a portion of oxygenated hydrocarbonsproduced in the hydrothermal hydrocatalytic reaction zone are recycledwithin the process and system to at least in part from the in situgenerated solvent, which is used in the biomass digestion process.Further, by controlling the degradation of carbohydrate in thehydrothermal hydrocatalytic reaction (e.g., hydrogenolysis process),hydrogenation reactions can be conducted along with the hydrogenolysisreaction at temperatures ranging from about 150° C. to 300° C. As aresult, a separate hydrogenation reaction section can optionally beavoided, and the fuel forming potential of the biomass feedstock fed tothe process can be increased. Further, it may be advantageous to use thein situ generated solvent as the organic solvent in the pretreatment.

In various embodiments, the fluid phase digestion medium in which thehydrothermal digestion and catalytic reduction reaction, in thehydrothermal hydrocatalytic reaction zone, are conducted may comprise anorganic solvent and water. Although any organic solvent that is at leastpartially miscible with water may be used as a digestion solvent,particularly advantageous organic solvents are those that can bedirectly converted into fuel blends and other materials without beingseparated from the alcoholic component being produced from thecellulosic biomass solids. That is, particularly advantageous organicsolvents are those that may be co-processed along with the alcoholiccomponent during downstream processing reactions into fuel blends andother materials. Suitable organic solvents in this regard may include,for example, ethanol, ethylene glycol, propylene glycol, glycerol,phenolics and any combination thereof. In situ generated organicsolvents are particularly desirable in this regard.

In some embodiments, the fluid phase digestion medium may comprisebetween about 1% water and about 99% water. Although higher percentagesof water may be more favorable from an environmental standpoint, higherquantities of organic solvent may more effectively promote hydrothermaldigestion due to the organic solvent's greater propensity to solubilizecarbohydrates and promote catalytic reduction of the solublecarbohydrates. In some embodiments, the fluid phase digestion medium maycomprise about 90% or less water by weight. In other embodiments, thefluid phase digestion medium may comprise about 80% or less water byweight, or about 70% or less water by weight, or about 60% or less waterby weight, or about 50% or less water by weight, or about 40% or lesswater by weight, or about 30% or less water by weight, or about 20% orless water by weight, or about 10% or less water by weight, or about 5%or less water by weight.

In some embodiments, catalysts capable of activating molecular hydrogenhydrothermal hydrocatalytic catalysts, which are capable of activatingmolecular hydrogen (e.g., hydrogenolysis catalyst) and conducting acatalytic reduction reaction may comprise a metal such as, for example,Cr, Mo, W, Re, Mn, Cu, Cd, Fe, Co, Ni, Pt, Pd, Rh, Ru, Ir, Os, andalloys or any combination thereof, either alone or with promoters suchas Au, Ag, Cr, Zn, Mn, Sn, Bi, B, O, and alloys or any combinationthereof. In some embodiments, the catalysts and promoters may allow forhydrogenation and hydrogenolysis reactions to occur at the same time orin succession of one another. In some embodiments, such catalysts mayalso comprise a carbonaceous pyropolymer catalyst containing transitionmetals (e.g., Cr, Mo, W, Re, Mn, Cu, and Cd) or Group VIII metals (e.g.,Fe, Co, Ni, Pt, Pd, Rh, Ru, Ir, and Os). In some embodiments, theforegoing catalysts may be combined with an alkaline earth metal oxideor adhered to a catalytically active support. In some or otherembodiments, the catalyst may be deposited on a catalyst support thatmay not itself be catalytically active.

In some embodiments, the hydrothermal hydrocatalytic catalyst maycomprise a slurry catalyst. In some embodiments, the slurry catalyst maycomprise a poison-tolerant catalyst. As used herein the term“poison-tolerant catalyst” refers to a catalyst that is capable ofactivating molecular hydrogen without needing to be regenerated orreplaced due to low catalytic activity for at least about 12 hours ofcontinuous operation. Use of a poison-tolerant catalyst may beparticularly desirable when reacting soluble carbohydrates derived fromcellulosic biomass solids that have not had catalyst poisons removedtherefrom. Catalysts that are not poison tolerant may also be used toachieve a similar result, but they may need to be regenerated orreplaced more frequently than does a poison-tolerant catalyst.

In some embodiments, suitable poison-tolerant catalysts may include, forexample, sulfided catalysts. In some or other embodiments, nitridedcatalysts may be used as poison-tolerant catalysts. Sulfided catalystssuitable for activating molecular hydrogen and buffers suitable for usewith such catalysts are described in commonly owned United States PatentApplication Publications US20120317872, US20130109896, andUS20120317873, and United States Published Patent ApplicationUS20140166221, each of which is incorporated herein by reference in itsentirety. Sulfiding may take place by treating the catalyst withhydrogen sulfide or an alternative sulfiding agent, optionally while thecatalyst is disposed on a solid support. In more particular embodiments,the poison-tolerant catalyst may comprise (a) sulfur and (b) Mo or W and(c) Co and/or Ni or mixtures thereof. The pH buffering agent, may besuitable be an inorganic salt, particularly alkali salts such as, forexample, potassium hydroxide, sodium hydroxide, and potassium carbonateor ammonia. In other embodiments, catalysts containing Pt or Pd may alsobe effective poison-tolerant catalysts for use in the techniquesdescribed herein. When mediating in situ catalytic reduction reactionprocesses, sulfided catalysts may be particularly well suited to formreaction products comprising a substantial fraction of glycols (e.g.,C₂-C₆ glycols) without producing excessive amounts of the correspondingmonohydric alcohols. Although poison-tolerant catalysts, particularlysulfided catalysts, may be well suited for forming glycols from solublecarbohydrates, it is to be recognized that other types of catalysts,which may not necessarily be poison-tolerant, may also be used toachieve a like result in alternative embodiments. As will be recognizedby one having ordinary skill in the art, various reaction parameters(e.g., temperature, pressure, catalyst composition, introduction ofother components, and the like) may be modified to favor the formationof a desired reaction product. Given the benefit of the presentdisclosure, one having ordinary skill in the art will be able to altervarious reaction parameters to change the product distribution obtainedfrom a particular catalyst and set of reactants.

In some embodiments, slurry catalysts suitable for use in the methodsdescribed herein may be sulfided by dispersing a slurry catalyst in afluid phase and adding a sulfiding agent thereto. Suitable sulfidingagents may include, for example, organic sulfoxides (e.g., dimethylsulfoxide), hydrogen sulfide, salts of hydrogen sulfide (e.g., NaSH),and the like. In some embodiments, the slurry catalyst may beconcentrated in the fluid phase after sulfiding, and the concentratedslurry may then be distributed in the cellulosic biomass solids usingfluid flow. Illustrative techniques for catalyst sulfiding that may beused in conjunction with the methods described herein are described inUnited States Patent Application Publication US20100236988 andincorporated herein by reference in its entirety.

In various embodiments, slurry catalysts used in conjunction with themethods described herein may have a particulate size of about 250microns or less. In some embodiments, the slurry catalyst may have aparticulate size of about 100 microns or less, or about 10 microns orless. In some embodiments, the minimum particulate size of the slurrycatalyst may be about 1 micron. In some embodiments, the slurry catalystmay comprise catalyst fines in the processes described herein.

Catalysts that are not particularly poison-tolerant may also be used inconjunction with the techniques described herein. Such catalysts mayinclude, for example, Ru, Pt, Pd, or compounds thereof disposed on asolid support such as, for example, Ru on titanium dioxide or Ru oncarbon. Although such catalysts may not have particular poisontolerance, they may be regenerable, such as through exposure of thecatalyst to water at elevated temperatures, which may be in either asubcritical state or a supercritical state.

In some embodiments, the catalysts used in conjunction with theprocesses described herein may be operable to generate molecularhydrogen. For example, in some embodiments, catalysts suitable foraqueous phase reforming (i.e., APR catalysts) may be used. Suitable APRcatalysts may include, for example, catalysts comprising Pt, Pd, Ru, Ni,Co, or other Group VIII metals alloyed or modified with Re, Mo, Sn, orother metals such as described in United States Patent PublicationUS20080300435 and incorporated herein by reference in its entirety.

In some embodiments, the alcoholic component formed from the cellulosicbiomass solids may be further reformed into a biofuel. Reforming thealcoholic component into a biofuel or other material may comprise anycombination and sequence of further hydrogenolysis reactions and/orhydrogenation reactions, condensation reactions, isomerizationreactions, oligomerization reactions, hydrotreating reactions,alkylation reactions, dehydration reactions, desulfurization reactions,and the like. The subsequent conversion reactions may be catalytic ornon-catalytic. In some embodiments, an initial operation of downstreamconversion may comprise a condensation reaction, often conducted in thepresence of a condensation catalyst, in which the alcoholic component ora product derived therefrom is condensed with another molecule to form ahigher molecular weight compound. As used herein, the term “condensationreaction” will refer to a chemical transformation in which two or moremolecules are coupled with one another to form a carbon-carbon bond in ahigher molecular weight compound, usually accompanied by the loss of asmall molecule such as water or an alcohol. An illustrative condensationreaction is the Aldol condensation reaction, which will be familiar toone having ordinary skill in the art. Additional disclosure regardingcondensation reactions and catalysts suitable for promoting condensationreactions is provided hereinbelow.

In some embodiments, methods described herein may further compriseperforming a condensation reaction on the alcoholic component or aproduct derived therefrom. In various embodiments, the condensationreaction may take place at a temperature ranging between about 5° C. andabout 500° C. The condensation reaction may take place in a condensedphase (e.g., a liquor phase) or in a vapor phase. For condensationreactions taking place in a vapor phase, the temperature may rangebetween about 75° C. and about 500° C., or between about 125° C. andabout 450° C. For condensation reactions taking place in a condensedphase, the temperature may range between about 5° C. and about 475° C.,or between about 15° C. and about 300° C., or between about 20° C. andabout 250° C.

Each reactor vessel preferably includes an inlet and an outlet adaptedto remove the product stream from the vessel or reactor. In someembodiments, the vessel in which at least some digestion occurs mayinclude additional outlets to allow for the removal of portions of thereactant stream. In some embodiments, the vessel in which at least somedigestion occurs may include additional inlets to allow for additionalsolvents or additives.

In various embodiments, the higher molecular weight compound produced bythe condensation reaction may comprise ≧C₄ hydrocarbons. In some orother embodiments, the higher molecular weight compound produced by thecondensation reaction may comprise ≧C₆ hydrocarbons. In someembodiments, the higher molecular weight compound produced by thecondensation reaction may comprise C₄-C₃₀ hydrocarbons. In someembodiments, the higher molecular weight compound produced by thecondensation reaction may comprise C₆-C₃₀ hydrocarbons. In still otherembodiments, the higher molecular weight compound produced by thecondensation reaction may comprise C₄-C₂₄ hydrocarbons, or C₆-C₂₄hydrocarbons, or C₄-C₁₈ hydrocarbons, or C₆-C₁₈ hydrocarbons, or C₄-C₁₂hydrocarbons, or C₆-C₁₂ hydrocarbons. As used herein, the term“hydrocarbons” refers to compounds containing both carbon and hydrogenwithout reference to other elements that may be present. Thus,heteroatom-substituted compounds are also described herein by the term“hydrocarbons.”

The particular composition of the higher molecular weight compoundproduced by the condensation reaction may vary depending on thecatalyst(s) and temperatures used for both the catalytic reductionreaction and the condensation reaction, as well as other parameters suchas pressure.

In some embodiments, a single catalyst may mediate the transformation ofthe alcoholic component into a form suitable for undergoing acondensation reaction as well as mediating the condensation reactionitself. In other embodiments, a first catalyst may be used to mediatethe transformation of the alcoholic component into a form suitable forundergoing a condensation reaction, and a second catalyst may be used tomediate the condensation reaction. Unless otherwise specified, it is tobe understood that reference herein to a condensation reaction andcondensation catalyst refers to either type of condensation process.Further disclosure of suitable condensation catalysts now follows.

In some embodiments, a single catalyst may be used to form a highermolecular weight compound via a condensation reaction. Without beingbound by any theory or mechanism, it is believed that such catalysts maymediate an initial dehydrogenation of the alcoholic component, followedby a condensation reaction of the dehydrogenated alcoholic component.Zeolite catalysts are one type of catalyst suitable for directlyconverting alcohols to condensation products in such a manner. Aparticularly suitable zeolite catalyst in this regard may be ZSM-5,although other zeolite catalysts may also be suitable.

In some embodiments, two catalysts may be used to form a highermolecular weight compound via a condensation reaction. Without beingbound by any theory or mechanism, it is believed that the first catalystmay mediate an initial dehydrogenation of the alcoholic component, andthe second catalyst may mediate a condensation reaction of thedehydrogenated alcoholic component. Like the single-catalyst embodimentsdiscussed previously above, in some embodiments, zeolite catalysts maybe used as either the first catalyst or the second catalyst. Again, aparticularly suitable zeolite catalyst in this regard may be ZSM-5,although other zeolite catalysts may also be suitable.

Various catalytic processes may be used to form higher molecular weightcompounds by a condensation reaction. In some embodiments, the catalystused for mediating a condensation reaction may comprise a basic site, orboth an acidic site and a basic site. Catalysts comprising both anacidic site and a basic site will be referred to herein asmulti-functional catalysts. In some or other embodiments, a catalystused for mediating a condensation reaction may comprise one or moremetal atoms. Any of the condensation catalysts may also optionally bedisposed on a solid support, if desired.

In some embodiments, the condensation catalyst may comprise a basiccatalyst comprising Li, Na, K, Cs, B, Rb, Mg, Ca, Sr, Si, Ba, Al, Zn,Ce, La, Y, Sc, Y, Zr, Ti, hydrotalcite, zinc-aluminate, phosphate,base-treated aluminosilicate zeolite, a basic resin, basic nitride,alloys or any combination thereof. In some embodiments, the basiccatalyst may also comprise an oxide of Ti, Zr, V, Nb, Ta, Mo, Cr, W, Mn,Re, Al, Ga, In, Co, Ni, Si, Cu, Zn, Sn, Cd, Mg, P, Fe, or anycombination thereof. In some embodiments, the basic catalyst maycomprise a mixed-oxide basic catalyst. Suitable mixed-oxide basiccatalysts may comprise, for example, Si—Mg—O, Mg—Ti—O, Y—Mg—O, Y—Zr—O,Ti—Zr—O, Ce—Zr—O, Ce—Mg—O, Ca—Zr—O, La—Zr—O, B—Zr—O, La—Ti—O, B—Ti—O,and any combination thereof. In some embodiments, the condensationcatalyst may further include a metal or alloys comprising metals suchas, for example, Cu, Ag, Au, Pt, Ni, Fe, Co, Ru, Zn, Cd, Ga, In, Rh, Pd,Ir, Re, Mn, Cr, Mo, W, Sn, Bi, Pb, Os, alloys and combinations thereof.Use of metals in the condensation catalyst may be desirable when adehydrogenation reaction is to be carried out in concert with thecondensation reaction. Basic resins may include resins that exhibitbasic functionality. The basic catalyst may be self-supporting oradhered to a support containing a material such as, for example, carbon,silica, alumina, zirconia, titania, vanadia, ceria, nitride, boronnitride, a heteropolyacid, alloys and mixtures thereof.

In some embodiments, the condensation catalyst may comprise ahydrotalcite material derived from a combination of MgO and Al₂O₃. Insome embodiments, the condensation catalyst may comprise a zincaluminate spinel formed from a combination of ZnO and Al₂O₃. In stillother embodiments, the condensation catalyst may comprise a combinationof ZnO, Al₂O₃, and CuO. Each of these materials may also contain anadditional metal or alloy, including those more generally referencedabove for basic condensation catalysts. In more particular embodiments,the additional metal or alloy may comprise a Group 10 metal such Pd, Pt,or any combination thereof.

In some embodiments, the condensation catalyst may comprise a basiccatalyst comprising a metal oxide containing, for example, Cu, Ni, Zn,V, Zr, or any mixture thereof. In some or other embodiments, thecondensation catalyst may comprise a zinc aluminate containing, forexample, Pt, Pd, Cu, Ni, or any mixture thereof.

In some embodiments, the condensation catalyst may comprise amulti-functional catalyst having both an acidic functionality and abasic functionality. Such condensation catalysts may comprise ahydrotalcite, a zinc-aluminate, a phosphate, Li, Na, K, Cs, B, Rb, Mg,Si, Ca, Sr, Ba, Al, Ce, La, Sc, Y, Zr, Ti, Zn, Cr, or any combinationthereof. In further embodiments, the multi-functional catalyst may alsoinclude one or more oxides from the group of Ti, Zr, V, Nb, Ta, Mo, Cr,W, Mn, Re, Al, Ga, In, Fe, Co, Ir, Ni, Si, Cu, Zn, Sn, Cd, P, and anycombination thereof. In some embodiments, the multi-functional catalystmay include a metal such as, for example, Cu, Ag, Au, Pt, Ni, Fe, Co,Ru, Zn, Cd, Ga, In, Rh, Pd, Ir, Re, Mn, Cr, Mo, W, Sn, Os, alloys orcombinations thereof. The basic catalyst may be self-supporting oradhered to a support containing a material such as, for example, carbon,silica, alumina, zirconia, titania, vanadia, ceria, nitride, boronnitride, a heteropolyacid, alloys and mixtures thereof.

In some embodiments, the condensation catalyst may comprise a metaloxide containing Pd, Pt, Cu or Ni. In still other embodiments, thecondensation catalyst may comprise an aluminate or a zirconium metaloxide containing Mg and Cu, Pt, Pd or Ni. In still other embodiments, amulti-functional catalyst may comprise a hydroxyapatite (HAP) combinedwith one or more of the above metals.

In some embodiments, the condensation catalyst may also include azeolite and other microporous supports that contain Group IA compounds,such as Li, Na, K, Cs and Rb. Preferably, the Group IA material may bepresent in an amount less than that required to neutralize the acidicnature of the support. A metal function may also be provided by theaddition of group VIIIB metals, or Cu, Ga, In, Zn or Sn. In someembodiments, the condensation catalyst may be derived from thecombination of MgO and Al₂O₃ to form a hydrotalcite material. Anothercondensation catalyst may comprise a combination of MgO and ZrO₂, or acombination of ZnO and Al₂O₃. Each of these materials may also containan additional metal function provided by copper or a Group VIIIB metal,such as Ni, Pd, Pt, or combinations of the foregoing.

The condensation reaction mediated by the condensation catalyst may becarried out in any reactor of suitable design, includingcontinuous-flow, batch, semi-batch or multi-system reactors, withoutlimitation as to design, size, geometry, flow rates, and the like. Thereactor system may also use a fluidized catalytic bed system, a swingbed system, fixed bed system, a moving bed system, or a combination ofthe above. In some embodiments, bi-phasic (e.g., liquid-liquid) andtri-phasic (e.g., liquid-liquid-solid) reactors may be used to carry outthe condensation reaction.

In some embodiments, an acid catalyst may be used to optionallydehydrate at least a portion of the reaction product. Suitable acidcatalysts for use in the dehydration reaction may include, but are notlimited to, mineral acids (e.g., HCl, H₂SO₄), solid acids (e.g.,zeolites, ion-exchange resins) and acid salts (e.g., LaCl₃). Additionalacid catalysts may include, without limitation, zeolites, carbides,nitrides, zirconia, alumina, silica, aluminosilicates, phosphates,titanium oxides, zinc oxides, vanadium oxides, lanthanum oxides, yttriumoxides, scandium oxides, magnesium oxides, cerium oxides, barium oxides,calcium oxides, hydroxides, heteropolyacids, inorganic acids, acidmodified resins, base modified resins, and any combination thereof. Insome embodiments, the dehydration catalyst may also include a modifier.Suitable modifiers may include, for example, La, Y, Sc, P, B, Bi, Li,Na, K, Rb, Cs, Mg, Ca, Sr, Ba, and any combination thereof. Themodifiers may be useful, inter alia, to carry out a concertedhydrogenation/dehydrogenation reaction with the dehydration reaction. Insome embodiments, the dehydration catalyst may also include a metal.Suitable metals may include, for example, Cu, Ag, Au, Pt, Ni, Fe, Co,Ru, Zn, Cd, Ga, In, Rh, Pd, Ir, Re, Mn, Cr, Mo, W, Sn, Os, alloys, andany combination thereof. The dehydration catalyst may beself-supporting, supported on an inert support or resin, or it may bedissolved in a fluid.

Various operations may optionally be performed on the alcoholiccomponent prior to conducting a condensation reaction. In addition,various operations may optionally be performed on a fluid phasecontaining the alcoholic component, thereby further transforming thealcoholic component or placing the alcoholic component in a form moresuitable for taking part in a condensation reaction. These optionaloperations are now described in more detail below.

As described above, one or more liquid phases may be present whendigesting cellulosic biomass solids. Particularly when cellulosicbiomass solids are fed continuously or semi-continuously to thehydrothermal (hydrocatalytic) digestion unit, digestion of thecellulosic biomass solids may produce multiple liquid phases in thehydrothermal digestion unit. The liquid phases may be immiscible withone another, or they may be at least partially miscible with oneanother. In some embodiments, the one or more liquid phases may comprisea phenolics liquid phase comprising lignin or a product formedtherefrom, an aqueous phase comprising the alcoholic component, a lightorganics phase, or any combination thereof. The alcoholic componentbeing produced from the cellulosic biomass solids may be partitionedbetween the one or more liquid phases, or the alcoholic component may belocated substantially in a single liquid phase. For example, thealcoholic component being produced from the cellulosic biomass solidsmay be located predominantly in an aqueous phase (e.g., an aqueous phasedigestion solvent), although minor amounts of the alcoholic componentmay be partitioned to the phenolics liquid phase or a light organicsphase. In various embodiments, the slurry catalyst may accumulate in thephenolics liquid phase as it forms, thereby complicating the return ofthe slurry catalyst to the cellulosic biomass solids in the mannerdescribed above. Alternative configurations for distributing slurrycatalyst particulates in the cellulosic biomass solids when excessivecatalyst accumulation in the phenolics liquid phase has occurred aredescribed hereinafter.

Accumulation of the slurry catalyst in the phenolics liquid phase may,in some embodiments, be addressed by conveying this phase and theaccumulated slurry catalyst therein to the same location where a fluidphase digestion medium is being contacted with cellulosic biomasssolids. The fluid phase digestion medium and the phenolics liquid phasemay be conveyed to the cellulosic biomass solids together or separately.Thusly, either the fluid phase digestion medium and/or the phenolicsliquid phase may motively return the slurry catalyst back to thecellulosic biomass solids such that continued stabilization of solublecarbohydrates may take place. In some embodiments, at least a portion ofthe lignin in the phenolics liquid phase may be depolymerized before orwhile conveying the phenolics liquid phase for redistribution of theslurry catalyst. At least partial depolymerization of the lignin in thephenolics liquid phase may reduce the viscosity of this phase and makeit easier to convey. Lignin depolymerization may take place chemicallyby hydrolyzing the lignin (e.g., with a base) or thermally by heatingthe lignin to a temperature of at least about 250° C. in the presence ofmolecular hydrogen and the slurry catalyst. Further details regardinglignin depolymerization and the use of viscosity monitoring as a meansof process control are described in commonly owned United StatesPublished Patent Application US20140117275, incorporated herein byreference in its entirety.

After forming the alcoholic component from the cellulosic biomasssolids, at least a portion of the alcoholic component may be separatedfrom the cellulosic biomass solids and further processed by performing acondensation reaction thereon, as generally described above. Processingof the alcoholic component that has partitioned between various liquidphases may take place with the phases separated from one another, orwith the liquid phases mixed together. For example, in some embodiments,the alcoholic component in a fluid phase digestion medium may beprocessed separately from a light organics phase. In other embodiments,the light organics phase may be processed concurrently with the fluidphase digestion medium.

Optionally, the fluid phase digestion medium containing the alcoholiccomponent may be subjected to a second catalytic reduction reactionexternal to the cellulosic biomass solids, if needed, for example, toincrease the amount of soluble carbohydrates that are converted into thealcoholic component and/or to further reduce the degree of oxygenationof the alcoholic components that are formed. For example, in someembodiments, a glycol or more highly oxygenated alcohol may betransformed into a monohydric alcohol by performing a second catalyticreduction reaction. The choice of whether to perform a condensationreaction on a monohydric alcohol or a glycol may be based on a number offactors, as discussed in more detail below, and each approach maypresent particular advantages.

In some embodiments, a glycol produced from the cellulosic biomasssolids may be fed to the condensation catalyst. Although glycols may beprone to coking when used in conjunction with condensation catalysts,particularly zeolite catalysts, the present inventors found the degreeof coking to be manageable in the production of higher molecular weightcompounds. Approaches for producing glycols from cellulosic biomasssolids and feeding the glycols to a condensation catalyst are describedin commonly owned United States Published Patent ApplicationUS20140121420, incorporated herein by reference in its entirety.

In some embodiments, a phenolics liquid phase formed from the cellulosicbiomass solids may be further processed. Processing of the phenolicsliquid phase may facilitate the catalytic reduction reaction beingperformed to stabilize soluble carbohydrates. In addition, furtherprocessing of the phenolics liquid phase may be coupled with theproduction of dried glycols or dried monohydric alcohols for feeding toa condensation catalyst. Moreover, further processing of the phenolicsliquid phase may produce methanol and phenolic compounds fromdegradation of the lignin present in the cellulosic biomass solids,thereby increasing the overall weight percentage of the cellulosicbiomass solids that may be transformed into useful materials. Finally,further processing of the phenolics liquid phase may improve thelifetime of the slurry catalyst.

These liquid phases or fluid phases can be used to remove water in thepretreatment as organic solvent, in the third contact zone, and thus beavailable for further processing.

Various techniques for processing a phenolics liquid phase produced fromcellulosic biomass solids are described in commonly owned United StatesPublished Patent Applications US20140121419, US20140117277, andUS20140121418, incorporated herein by reference in its entirety. Asdescribed therein, in some embodiments, the viscosity of the phenolicsliquid phase may be reduced in order to facilitate conveyance orhandling of the phenolics liquid phase. As further described therein,deviscosification of the phenolics liquid phase may take place bychemically hydrolyzing the lignin and/or heating the phenolics liquidphase in the presence of molecular hydrogen (i.e., hydrotreating) todepolymerize at least a portion of the lignin present therein in thepresence of accumulated slurry catalyst. Deviscosification of thephenolics liquid phase may take place before or after separation of thephenolics liquid phase from one or more of the other liquid phasespresent, and thermal deviscosification may be coupled to the reaction orseries of reactions used to produce the alcoholic component from thecellulosic biomass solids. Moreover, after deviscosification of thephenolics liquid phase, the slurry catalyst may be removed therefrom.The catalyst may then be regenerated, returned to the cellulosic biomasssolids, or any combination thereof.

In some embodiments, heating of the cellulosic biomass solids and thefluid phase digestion medium to form soluble carbohydrates and aphenolics liquid phase may take place while the cellulosic biomasssolids are in a pressurized state. As used herein, the term “pressurizedstate” refers to a pressure that is greater than atmospheric pressure (1bar). Heating a fluid phase digestion medium in a pressurized state mayallow the normal boiling point of the digestion solvent to be exceeded,thereby allowing the rate of hydrothermal digestion to be increasedrelative to lower temperature digestion processes. In some embodiments,heating the cellulosic biomass solids and the fluid phase digestionmedium may take place at a pressure of at least about 30 bar. In someembodiments, heating the cellulosic biomass solids and the fluid phasedigestion medium may take place at a pressure of at least about 60 bar,or at a pressure of at least about 90 bar. In some embodiments, heatingthe cellulosic biomass solids and the fluid phase digestion medium maytake place at a pressure ranging between about 30 bar and about 430 bar.In some embodiments, heating the cellulosic biomass solids and the fluidphase digestion medium may take place at a pressure ranging betweenabout 50 bar and about 330 bar, or at a pressure ranging between about70 bar and about 130 bar, or at a pressure ranging between about 30 barand about 130 bar.

To facilitate a better understanding of the present invention, thefollowing examples of preferred embodiments are given. In no way shouldthe following examples be read to limit, or to define, the scope of theinvention.

ILLUSTRATIVE EXAMPLES Example 1 Metals Removal by Strong Acid

75.1 grams of 1.0 wt % sulfuric acid in deionized water were contactedwith 10.0 grams of southern pine chips of nominal 5 mm×4 mm×3 mm sizeand 39% moisture, by shaking longitudinally in a Teflon capped jarovernight at room temperature. Liquid was separated via filtration in afilter funnel using Whatman GF/F paper, and analyzed viainductively-coupled plasma atomic spectroscopy for metals.

A separate sample of the untreated wood was combusted, and the residualmetals and ash dissolved in concentrated sulfuric acid for analysis byatomic spectroscopy.

Results indicated removal of 11-ppm silicon, 35 ppm phosphorous, 61 ppmmanganese, 209 ppm magnesium, 12 ppm aluminum, 3.6 ppm iron, 530 ppmpotassium, 135 ppm sodium, and 811 ppm calcium via the 1% acidtreatment. This corresponded to complete removal of metals withinanalytical error, except for manganese which was only indicated to beremoved at 67% of the amount assess for the untreated wood sample

Example 2 Metals Removal by Weak Acid

Example 1 was repeated with use of 1.5 weight percent acetic acid indeionized water as the treatment solution. 49.2 grams of this solutionwere contacted with 7.31 grams of the untreated southern pine woodchips, again with shaking overnight at room temperature. Analysis of theliquid filtrate by atomic spectroscopy indicated removal of 13-ppmsilicon, 34-ppm manganese, 135 ppm magnesium, 323 ppm potassium, 61 ppmsodium, and 457 ppm calcium via the 1% acid treatment. The amountsremoved corresponded to 35-100% of the amount of metal assessed aspresent on the initial untreated wood sample. Chlorine was also removed,as indicated by the presence of up to 10 ppm chlorine in treatmenteffluents.

These results show that metals and chloride present in wood can beremoved by contacting with dilute sulfuric or carboxylic (acetic) acid.Metal removal is improved via use of strong acid (sulfuric vscarboxylic).

Example 3 and 4 Metals Removal by Deionized Water

For example 3, 100-grams of 0.05 wt % sulfuric acid in deionized waterwere contacted with 20.0 grams of southern pine wood chips (39%moisture) by shaking longitudinally overnight at room temperature in ajar with Teflon lined cap. Analysis of filtered supernatant via atomicspectroscopy revealed 57 ppm manganese, 213 ppm magnesium, 467 ppmpotassium, and 860 ppm calcium, corresponding to complete removal of allmetals except manganese, for which 63% removal was indicated.

For example 4 with deionized water only as treatment agent, removalpotassium and sodium was complete within measurement error, whileremoval of manganese was negligible, and removal of magnesium andcalcium was only 12 to 13 percent of that present in the untreated wood.

These results indicate that even a small amount (0.05 wt %) of acid iseffective in dramatically improving the metals removal in pretreatment,especially for metals known to form multivalent cations.

Example 5 and 6 Repetitive Contacting

For example 5, wood from example 3 was continued with two morecontacting with fresh 0.05 wt % sulfuric acid solution, followed byremoval by filtration. The amount of manganese removed when summed withthat from the first cycle, now indicated complete removal relative tothe amount analyzed for the untreated wood sample.

Example 6 entailed two more contacting cycles of the wood from example5, with deionized water. Calcium and magnesium removal summed over allthree cycles corresponded to only 29-30% of total, while manganeseremoval remained negligible.

These examples demonstrate the value of repetitive contacting with freshtreatment liquid to overcome equilibrium, and the benefits of low levelsof acidity in removing metals which can form multivalent cations insolution.

Examples 7-9 Acidic Solution Wash

Southern pine wood minichips of nominal 5-mm×4 mm×3 mm dimension werestatically treated for 18 hours via a 0.05 wt % sulfuric acid solution.After the contacting, liquid was removed by vacuum filtration andanalyzed for total organic carbon. Contacting in example 7 was conductedat 24° C. room temperature, and yielded loss of 0.16 percent of thecarbon components in wood, to the liquid phase treatment n to the liquidduring treatment to remove chloride and metals.

For example 8, the contacting temperature was increased to 49° C., andthe loss of carbon-containing species to the treatment liquidcorresponded to 0.25 percent.

For example 9, the contacting temperature was increased to 60° C., andthe loss of carbon containing species from the wood was 0.31 percent.This indicates that the loss of carbohydrates is minimal.

Examples 10-12 Acidic Solution Wash

For examples 10-12, the contacting liquid was changed to 0.05 wt %sulfuric acid. Losses of carbon containing species from wood werediminished relative to those observed in neutral water. At 24° C., only0.08 percent of carbon was lost from the wood to the liquid solution(example 10). At 49° C., loss of carbon containing species was increasedto 0.12 percent of total (example 11), while at 60° C., the lossesincreased to only 0.16 percent (example 12).

Removal of multivalent metals such as magnesium and calcium was againobserved to increase in the present of dilute acid, relative to theremoval effected in the presence of water only.

Example 13-15 Acidic Solution Wash

A 25-mm inside diameter by 450 mm long glass chromatography column waspacked with 73.0 grams of ground softwood (Eco shredder Model #) at 39%moisture. 70 grams of 0.05% H₂SO₄ were added upflow at a flowrate of 4.1ml/min, visibly filling 40% of the lower portion of the bed, at asuperficial rate of 1.1 bed volumes (BV) per hour.

After injection of the 0.35 bed volume slug of acid treatment, feed wasimmediately switched to deionized water for another 2.47 bed volumes, topush the acid slug through the bed and continue the wash treatment.

Effluent samples were analyzed for chloride and metals, for comparisonwith the amount of these impurities in the wood sample charged. Resultsindicated greater than 80% removal of chloride, sodium, and potassium.Only 16 percent of calcium and 21 percent of magnesium was removed, andonly 4% of divalent metal manganese.

Example 13 was repeated with loading of 75.1 grams of an alternate woodsample at 51% moisture. Sulfuric acid strength was increased to 1.0 wt%. Removal of chloride, potassium, sodium, calcium, and magnesium wasnow indicated to be 100%, while removal of divalent manganese was 71% ofthat present in the wood feed.

Example 13 was repeated with initial charging of 130.1 wet grams at67.1% moisture content, of wood that had been prestreamed to watersaturate for one hour in a vegetable steamer. Results now indicatedcomplete removal of all measured species present in the original woodsample, including divalent manganese.

Examples 13-15 demonstrate use of less than one bed volume of sulfuricacid treatment to remove metals, and simultaneously remove chloride.Metals removal was improved by increasing acid strength from 0.05% to1.0 wt %, while pre-steaming to saturate the wood improved the removalof the most resistant component, divalent metal manganese.Pre-saturation with steam to eliminate trapped gas from the wood matrixmay improve contacting with the treatment solution, improving theremoval of impurities.

Examples 16-20 Acid and Base Wash

A series of biomass pretreatment experiments were conducted in 15-mm or25-mm diameter glass chromatography columns (Ace Glassware), withpretreatment solutions fed from glass buret via a Low-Flow CompactMetering Pump, 30 mL/min maximum, 115 VAC, from Cole Parmer(WU-07115-10). A retriever 500 fraction collector from Isco/Teledyne wasused to collect sample fractions. Southeaster US pine wood was ground toa dimension of approximately 8-mm×3-mm×3-mm using a “Retsch Grinder”Model SM100 is a rotating knife blade grinder.

Samples of the feed wood, and wood following treatment were analyzed formetals via combustion, then dissolution of the resulting ash in sulfuricacid for analysis by plasma emission spectroscopy. A second sample wasanalyzed by ion chromatography to determine the chloride content of thewood samples.

Treatments for the biomass wash sequence entailed use of 1% sulfuricacid, 0.5N KOH, deionized water, and 25% ethanol in deionized water.

The volume of the bed of wood treated was determined from the knowncolumn diameter, and the measured length of the wood bed, which wasretained either via adjustable plungers, or silane treated glass woolplugs. Packing density for the ground wood samples ranged from 0.21 to0.25 dry grams per milliliter of bed volume.

Results of the Treatment Experiments are Tabulated in Table 1.

Comparison of Examples 16 and 20 where no acid was used and Examples17-19 shows that acid is important for removal of the transition metalssuch as Manganese, which are presumed to be ion exchanged into the woodmatrix. No detectable transition metal removal occurred, in the absenceof acid addition. The amount of acid used to treat the wood could bevery small, with as low as 0.14 bed volumes of acid used, followed bywaster wash to flush the acid zone through the bed. Acid addition alsoimproved the removal of calcium and magnesium salts.

As the flowrate of treatment decreased, removal of calcium, manganese,and magnesium increased under otherwise similar treatment conditions.This can be shown by higher concentrations of leached metals andchlorides observed in the effluent samples, as treatment flowratedecreases.

Base addition was effective in removing phosphorous and improved theremoval of chloride, as evidence in Examples 18 and 19. However, it canbe seen from example 20 that metals such as Manganese and Magnesium isnot effectively removed without the acid.

Combinations of acid wash and base wash were most effective in removingboth metals and chloride contaminants, plus phosphorus. The examplesshow simultaneous removal of both metals and chlorides via thetreatments comprising this invention.

The acid and base washes may be used in any order. If the ensuingprocess step is best operated under acidic conditions, such as in diluteacid hydrolysis of biomass, then use of a base wash followed by acidwash may be most efficient, as it is then not necessary to rinse all ofthe acidic treatment fluid out of the bed, before adding the solids inthe bed to the process. On the other hand, if base is used to neutralizeacids in the process or as a hydrolysis agent, then use of acid washfollowed by base wash may be most efficient.

TABLE 1 Biomass pretreatment experiments Parameter Units Ex.16 Ex.17Ex.18 Ex.19 Ex.20 Flowrate BV/h 0.71 0.46 0.62 0.78 0.73 1% H2SO4 BV0.00 0.28 0.99 0.14 0.00 0.5N KOH BV 0 0 0.99 0.14 0.26 DI Water BV 3.392.20 0.99 2.48 2.33 25% EtOH BV 0.00 0.00 1.98 0.00 0.00 Total BV BV3.39 2.48 4.95 2.76 2.59 Phosphorus % remove   32.2% 22.0% 100.0% 100.0%  100.0% Manganese % remove  −6.5% 90.3%  96.8%  71.0%  −9.7% Iron %remove   73.9% 78.3%  91.3%  87.0%    91.3% Magnesium % remove   26.8%92.9%  98.4%  85.0%    37.8% Calcium % remove   48.1% 92.9%  98.3% 86.9%    51.9% Chloride % remove   54.5% 72.7%  80.0%  85.5%    83.6%

Example 21 Solvent Drying

A 15-mm inside diameter×24 inch glass chromatography column was chargedwith 23 inches of ground pine wood with moisture content of 52.4%,measured by drying of a sample in a vacuum oven overnight at 86° C. 39.6grams of wood were charged. Ethanol (less than 1000 ppm H₂O) was chargedas solvent to a feed buret. The solvent was flowed upflow through thecolumn at 0.8 ml/min using a Low-Flow Compact Metering Pump, 30 mL/minmaximum, 115 VAC, from Cole Panner (WU-07115-10). A retriever 500fraction collector from Isco/Teledyne was used to collect samplefractions. Southeaster US pine wood was ground to a dimension ofapproximately 8-mm×3-mm×3-mm using a “Retsch Grinder” Model SM100 is arotating knife blade grinder.

Samples were collected in 50-ml fractions (0.48 bed volumes MVP, andanalyzed by Karl Fisher titration for water content. At the end of 3.9bed volumes of solvent wash, the cumulative water removed correspondedto 103% of the assessed water content of the initially charged wood.This result indicates virtual complete removal of water via use ofethanol as solvent, under the conditions described. The results ofdrying by ethanol are shown in Table 2. Table 2 also shows furtherimpurity removals via ethanol treatment. In addition to phosphorus, somechloride and metal salts are removed, as expected for the early sampleswhere significant water is eluted. Thus, it may be beneficial to solventdry, particularly if the solvent is in-situ generated solvents that mayalso be further process to products.

TABLE 2 Ethanol drying of wood chips Ca Cl Fe K Mg Mn P S Sx BV % H2Og-H2O (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (wt %) 1 0.48 25.4%10.922 1.69 <1.0 3.3 1.46 <1.0 0.16 <1.0 <0.001 2 0.97 13.4% 5.762 10.3516.37 2.92 45.7 24.92 0.44 15.16 0.001 3 1.45  6.4% 2.752 2.11 <1.0 3.065.53 <1.0 <1.0 2.05 <0.001 4 1.94  2.6% 1.1008 1.75 <1.0 3.25 55.96 <1.0<1.0 40.99 0.004 5 2.42  1.1% 0.4558 3.3 <1.0 3.72 14.16 6.31 <1.0 9.720.002 6 2.91  0.7% 0.2795 1.56 <1.0 3.03 <1.0 <1.0 <1.0 0.69 <0.001 73.39  0.4% 0.1806 2.61 <1.0 3.24 18.26 2.23 <1.0 11.92 0.001 8 3.88 0.1% 0.0559 3.32 <1.0 3.53 <1.0 <1.0 <1.0 1.63 <0.001 drain 0.58  0.0%0.0043 1.71 <1.0 3.08 <1.0 <1.0 <1.0 0.7 <0.001 21.5129 2.77 <1.0 2.98<1.0 <1.0 <1.0 <1.0 <0.001

Example 22 Gas displacement

A 15-mm glass chromatography column was packed to a bed length of 22.5inches with ground wood. The column was subjected to 1% sulfuric acid,water, and 0.5N base wash, followed by a final water rinse.Approximately 60 ml of final aqueous phase was drained from the bed atthe end of the treatment sequence, representing 59% of the total bedvolume.

This example represents draining of interstitial liquid from a water-wetbed, to remove a substantial (greater than 50%) portion of the liquidused to push acid or base wash through the bed. The drained water can bere-used for subsequent wash steps.

What is claimed is:
 1. A method for selective removal of a detrimentalmetals and their anion species from a cellulosic biomass solidscomprising: a. providing a detrimental species-containing cellulosicbiomass solids; b. introducing said detrimental species-containingcellulosic biomass solids from an inlet into a treatment vessel, saidcellulosic biomass solids having a true interstitial volume in saidvessel; c. introducing an acidic solution having a pH of at most 4 froman inlet to said cellulosic biomass solids containing vessel at atemperature in the range of 0° C. to 60° C. in an amount to fill atleast about 5% bed volume to at most about 40% bed volume of said trueinterstitial volume; d. subsequently to step c, introducing an aqueoussolution having a pH of at least 5 from an inlet to said acidiccellulosic biomass solids-containing vessel, thereby producing washedcellulosic biomass solids having reduced detrimental species contentcompared to the detrimental species-containing cellulosic biomass solidsand an acidic water effluent, wherein said acidic water effluent is inthe range of about 3 parts to about 0.5 parts relative to about 1 partof detrimental species-containing cellulosic biomass solids (dry basis);e. introducing a removal stream comprising a gas stream or an organicsolvent solution from an inlet to the vessel containing the washedcellulosic biomass solids thereby producing a pretreated cellulosicbiomass solids with reduced water content compared to the water washedcellulosic biomass solids and an aqueous effluent; f. discharging thepretreated cellulosic biomass solids from an outlet and transferring atleast a portion of the discharged pretreated biomass solids to adigestion and/or reaction zone; g. recycling at least a first portion ofthe aqueous effluent to produce acidic solution; and h. recycling atleast a second portion of the aqueous effluent as an aqueous solution.2. The method of claim 1 wherein the acidic solution comprises aninorganic acid.
 3. The method of claim 2 wherein the inorganic acid issulfuric acid.
 4. The method of claim 2 wherein the inorganic acid is aphosphoric acid.
 5. The method of claim 3 wherein the sulfuric acid ispresent in an amount of 0.01 wt % to 1 wt % based on the acidicsolution.
 6. The method of claim 4 wherein the phosphoric acid ispresent in an amount of 0.01 wt % to 1 wt % based on the acidicsolution.
 7. The method of claim 2 wherein the inorganic acid is nitricacid.
 8. The method of claim 7 wherein the nitric acid is present in anamount of 0.01 wt % to 1 wt % based on the acidic solution.
 9. Themethod of claim 1 wherein the acidic solution comprises a carboxylicacid.
 10. The method of claim 9 wherein the carboxylic acid is selectedfrom the group consisting of acetic acid, levulinic acid, lactic acid,formic acid, propionic acid, and mixtures thereof.
 11. The method ofclaim 9 wherein the carboxylic acid is present in an amount of 0.1 wt %to 5 wt % based on the acidic solution.
 12. The method of claim 1wherein the organic solvent is a solvent used in the digestion and/orreaction zone.
 13. The method of claim 1 wherein, in the digestionand/or reaction zone, the treated cellulosic biomass is contacted with ahydrothermal hydrocatalytic catalyst in the presence of hydrogen in thepresence of a digestion solvent thereby producing an intermediateoxygenated product stream; at least a portion of the oxygenatedintermediate product stream is converted to a hydrocarbon product streamcomprising hydrocarbons and water; and at least a portion of the wateris separated and recycled to form at least a portion of the aqueoussolution.
 14. The method of claim 1 wherein, in the digestion and/orreaction zone, the treated cellulosic biomass is contacted with ahydrothermal hydrocatalytic catalyst in the presence of hydrogen in thepresence of a digestion solvent thereby producing an intermediateoxygenated product stream; at least a portion of the oxygenatedintermediate product stream is converted to a hydrocarbon product streamcomprising hydrocarbons and water; and at least a portion of the wateris separated and recycled to form at least a portion of the aqueoussolution.
 15. The method of claim 14 wherein, the oxygenatedintermediate product steam comprises oxygenated hydrocarbons and water,and at least a portion of the water is separated and recycled form atleast a portion of the aqueous solution.
 16. The method of claim 1wherein the inlet of steps c, d, and e are the same inlet.
 17. Themethod of claim 1 wherein the inlet of step c and step e are a differentinlet.
 18. A method for selective removal of a detrimental metals andtheir anion species from a cellulosic biomass solids comprising: a.providing a detrimental species-containing cellulosic biomass solids; b.introducing said detrimental species-containing cellulosic biomasssolids from an inlet into a treatment vessel, said cellulosic biomasssolids having a true interstitial volume in said vessel; c. introducingan acidic solution having a pH of at most 4 from an inlet to saidcellulosic biomass solids containing vessel at a temperature in therange of 0° C. to 60° C. in an amount to fill at least about 5% bedvolume to at most about 40% bed volume of said true interstitial volume;d. subsequently to step c, introducing an aqueous solution having a pHof at least 5 from an inlet to said acidic cellulosic biomasssolids-containing vessel, thereby producing washed cellulosic biomasssolids having reduced detrimental species content compared to thedetrimental species-containing cellulosic biomass solids and an acidicwater effluent; e. introducing a base solution having a pH of at least 9from an inlet to said washed cellulosic biomass solids containing vesselat a temperature in the range of 0° C. to 60° C. in an amount to fill atleast about 5% bed volume to at most about 40% bed volume of said trueinterstitial volume; f. subsequently to step e, introducing an aqueoussolution having a pH of at most 8 from an inlet to said basic cellulosicbiomass solids-containing vessel, thereby producing second washedcellulosic biomass solids having reduced detrimental species contentcompared to the detrimental species-containing cellulosic biomass solidsand an basic water effluent; g. wherein the combined amount of saidacidic water effluent and said basic water effluent is in the range ofabout 3 parts to about 0.5 parts relative to about 1 part of detrimentalspecies-containing cellulosic biomass solids (dry basis) h. introducinga removal stream comprising a gas stream or an organic solvent solutionfrom an inlet to the vessel containing the second washed cellulosicbiomass solids thereby producing a pretreated cellulosic biomass solidswith reduced water content compared to the second water washedcellulosic biomass solids and a second aqueous effluent; i. dischargingthe pretreated cellulosic biomass solids from an outlet and transferringat least a portion of the discharged pretreated biomass solids to adigestion and/or reaction zone; j. recycling at least a first portion ofthe aqueous effluent to produce acidic solution; k. recycling at least afirst portion of the second aqueous effluent to produce base solution;and l. recycling at least a second portion of the aqueous effluent andat least a second portion of the second aqueous effluent as an aqueoussolution.
 19. The method of claim 18 wherein the base solution comprisesa base selected from sodium hydroxide, potassium hydroxide or ammonia.20. The method of claim 18 wherein the acidic solution comprises aninorganic acid or an organic acid.
 21. The method of claim 18 whereinthe organic solvent is a solvent used in the digestion and/or reactionzone.
 22. The method of claim 18 wherein, in the digestion and/orreaction zone, the treated cellulosic biomass is contacted with ahydrothermal hydrocatalytic catalyst in the presence of hydrogen in thepresence of a digestion solvent thereby producing an intermediateoxygenated product stream; at least a portion of the oxygenatedintermediate product stream is converted to a hydrocarbon product streamcomprising hydrocarbons and water; and at least a portion of the wateris separated and recycled to form at least a portion of the aqueoussolution.
 23. The method of claim 18 wherein, in the digestion and/orreaction zone, the treated cellulosic biomass is contacted with ahydrothermal hydrocatalytic catalyst in the presence of hydrogen in thepresence of a digestion solvent thereby producing an intermediateoxygenated product stream; at least a portion of the oxygenatedintermediate product stream is converted to a hydrocarbon product streamcomprising hydrocarbons and water; and at least a portion of the wateris separated and recycled to form at least a portion of the aqueoussolution.
 24. The method of claim 23 wherein, the oxygenatedintermediate product steam comprises oxygenated hydrocarbons and water,and at least a portion of the water is separated and recycled form atleast a portion of the aqueous solution.
 25. The method of claim 18wherein the inlet of steps c, d, e, f and h are the same inlet.
 26. Themethod of claim 18 wherein the inlet of step c and step h are adifferent inlet.
 27. A method for selective removal of a detrimentalmetals and their anion species from a cellulosic biomass solidscomprising: a. providing a detrimental species-containing cellulosicbiomass solids; b. introducing said detrimental species-containingcellulosic biomass solids from an inlet into a treatment vessel, saidcellulosic biomass solids having a true interstitial volume in saidvessel; c. introducing a base solution having a pH of at least 9 from aninlet to said cellulosic biomass solids containing vessel at atemperature in the range of 0° C. to 60° C. in an amount to fill atleast about 5% bed volume to at most about 40% bed volume of said trueinterstitial volume; d. subsequently to step c, introducing an aqueoussolution having a pH of at most 8 from an inlet to said basic cellulosicbiomass solids-containing vessel, thereby producing washed cellulosicbiomass solids having reduced detrimental species content compared tothe detrimental species-containing cellulosic biomass solids and anbasic water effluent; e. introducing a base solution having a pH of atmost 4 from an inlet to said washed cellulosic biomass solids containingvessel at a temperature in the range of 0° C. to 60° C. in an amount tofill at least about 5% bed volume to at most about 40% bed volume ofsaid true interstitial volume; f. subsequently to step e, introducing anaqueous solution having a pH of at least 5 from an inlet to said basiccellulosic biomass solids-containing vessel, thereby producing secondwashed cellulosic biomass solids having reduced detrimental speciescontent compared to the detrimental species-containing cellulosicbiomass solids and an acidic water effluent; g. wherein the combinedamount of said acidic water effluent and said basic water effluent is inthe range of about 3 parts to about 0.5 parts relative to about 1 partof detrimental species-containing cellulosic biomass solids (dry basis)h. introducing a removal stream comprising a gas stream or an organicsolvent solution from an inlet to the vessel containing the secondwashed cellulosic biomass solids thereby producing a pretreatedcellulosic biomass solids with reduced water content compared to thesecond water washed cellulosic biomass solids and a second aqueouseffluent; i. discharging the pretreated cellulosic biomass solids froman outlet and transferring at least a portion of the dischargedpretreated biomass solids to a digestion and/or reaction zone; j.recycling at least a first portion of the aqueous effluent to producebase solution; k. recycling at least a first portion of the secondaqueous effluent to produce acidic solution; and l. recycling at least asecond portion of the aqueous effluent and at least a second portion ofthe second aqueous effluent as an aqueous solution.
 28. The method ofclaim 27 wherein the base solution comprises a base selected from sodiumhydroxide, potassium hydroxide or ammonia
 29. The method of claim 27wherein the acidic solution comprises an inorganic acid or an organicacid.
 30. The method of claim 27 wherein the organic solvent is asolvent used in the digestion and/or reaction zone.
 31. The method ofclaim 27 wherein, in the digestion and/or reaction zone, the treatedcellulosic biomass is contacted with a hydrothermal hydrocatalyticcatalyst in the presence of hydrogen in the presence of a digestionsolvent thereby producing an intermediate oxygenated product stream; atleast a portion of the oxygenated intermediate product stream isconverted to a hydrocarbon product stream comprising hydrocarbons andwater; and at least a portion of the water is separated and recycled toform at least a portion of the aqueous solution.
 32. The method of claim27 wherein, in the digestion and/or reaction zone, the treatedcellulosic biomass is contacted with a hydrothermal hydrocatalyticcatalyst in the presence of hydrogen in the presence of a digestionsolvent thereby producing an intermediate oxygenated product stream; atleast a portion of the oxygenated intermediate product stream isconverted to a hydrocarbon product stream comprising hydrocarbons andwater; and at least a portion of the water is separated and recycled toform at least a portion of the aqueous solution.
 33. The method of claim32 wherein, the oxygenated intermediate product steam comprisesoxygenated hydrocarbons and water, and at least a portion of the wateris separated and recycled form at least a portion of the aqueoussolution.
 34. The method of claim 27 wherein the inlet of steps c, d, e,f and h are the same inlet.
 35. The method of claim 27 wherein the inletof step c and step h are a different inlet.
 36. The method of claim 1wherein the loss of carbohydrate from the washing is less than 10% byweight, based on the carbohydrates present in the biomass (dry basis).37. The method of claim 18 wherein the loss of carbohydrate from thewashing is less than 10% by weight, based on the carbohydrates presentin the biomass (dry basis).
 38. The method of claim 27 wherein the lossof carbohydrate from the washing is less than 10% by weight, based onthe carbohydrates present in the biomass (dry basis).